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Thread: Coolant Leak...Radiator Cap??

  1. #1
    Standard Member Stevie76's Avatar
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    Coolant Leak...Radiator Cap??

    Hi,

    Looking for a bit of advice. Basically I noticed a teaspoon of coolant on the garage floor so been trying to determine where it's come from.

    I pulled the bellypan which had a bit more coolant in it and the RHS upper fairing and noticed a small wet patch at the bottom of the road. No visible issues with the rad (Got a guard on it). I ran the bike for a while and could not see anything untoward. After it cooler down for a while I took the rad cap off and it felt a bit a bit wet on the edges so I'm wondering if one the pressure builds up when the bike gets hot if it's pushing coolant past the cap? Anyone have any thoughts on this? Have there been any problems with blow past on the rad caps?

    Any advice would be very much appreciated.

    Cheers
    Steve

  2. #2
    Forum Moderator alex's Avatar
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    Re: Coolant Leak...Radiator Cap??

    Rad caps do fail.
    They are cheap to replace.
    When they fail they tend to allow fluid build up in the coolant expansion tank and over fill it. Getting the result you see.


    The far more expensive reason would be a blown head gasket...but try the rad cap first.

    - Alex

  3. #3
    Standard Member Stevie76's Avatar
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    Re: Coolant Leak...Radiator Cap??

    Thanks Alex. I'm definitely thinking either issue with the rad itself or the cap. My HP4 has only done 3k miles of road use so would be odd for the HG to go? The expansion bottle is about half full and the rubber bung was still properly located. Only place I could see coolant was on the rad guard too so can't see it collecting there if it was HG?

    Hopefully you can see the small collection of coolant on the rad guard on the pic below.

    Will get a new cap and monitor it. Got it going in for service and MOT too soon so can get dealer to check.

    Last edited by Stevie76; 30th April 2018 at 07:31 AM. Reason: Update

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